I’ve looked at this at great length at various times over the last couple of
years and each time I think about doing this (because I’m old school and to me
FSK seems like ‘real’ RTTY and AFSK is ‘play RTTY’) I decide not to because the
filters of the 590 won’t go any tighter than 250Hz. In a busy contest, I run
at 200Hz and sometimes as tight as 150Hz. RTTY shift is 170Hz but I find that
the 150Hz filter setting in the 590 has enough at the edges to still get
perfect decodes.
Of course I’m wrong about AFSK being play RTTY, it’s as real as FSK and
providing your levels are correct (ie zero ALC indicated on the radio), very
clean indeed.
So apart from the technical challenge of making it work, I wouldn’t even bother.
73 Keith G6NHU
> On 23 Feb 2018, at 19:49, groupsrichart@gmail.com wrote:
>
> I would like to hear from anyone who is successfully keying the FSK and PTT
> lines via the ACC2 connector on the rear panel of the TS-590SG. What serial
> adapter and what hardware interface are you using to do so?
>
> I have tried two different interfaces using optoisolators to attempt FSK and
> PTT keying from a serial card to the rear panel ACC2 connector. Both attempts
> have failed. I am using MMTTY software for keying and I do get the requisite
> signal change on TXD pin 3 (FSK) and RTS pin 7 (PTT) lines. I have also
> verified proper setup of the '590 by manually grounding the inputs PKS pin 9
> (PTT) and RTTY pin 2 (FSK) on the ACC2 connector.
>
> However, I *think* the problem lies with the serial card not providing enough
> voltage/current for the optoisolators to completely turn on and provide a
> hard ground to the ACC2 inputs. I have tried two different serial cards and
> one swings from -4.9 to +5.0 VDC on the data lines and the other card swings
> from -3.8 to +3.9 VDC. The cards I am using are a two port generic PCI
> Express SI-PEX15037 and a four port Perle Fast 4 PCI card. Does anyone know
> of a serial card that has a full -12 to +12 VDC swing?
>
> One of the hardware interfaces has 4N25 optoisolators and the other uses
> Fairchild FOD852 optoisolators. There are 1K series resistors in the input
> line to the optoisolators and I have tried various values (100, 220 & 470Ω)
> with limited success but nothing consistent.
>
> While my objective was to keep the rig isolated from the computer, I am
> thinking about building an interface that uses NPN transistors for keying. Is
> anyone using NPN transistors to key their '590? Are you tying the ground from
> pin 5 of the RS-232 port to the pin 4, 8 or 12 ground of the ACC2?
>
> Any input is appreciated...I have been off RTTY since purchasing this rig in
> November and I want to get back on the bands.
>
> Thanks,
>
> Tim WS4V
>
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